/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard.classfile.visitor;

import proguard.classfile.*;

/**
 * This <code>ClassVisitor</code> lets a given <code>ClassVisitor</code> travel to the first concrete subclasses down in
 * its hierarchy of abstract classes and concrete classes.
 *
 * @author Eric Lafortune
 */
public class ConcreteClassDownTraveler implements ClassVisitor {
    private final ClassVisitor classVisitor;

    /**
     * Creates a new ConcreteClassDownTraveler.
     * 
     * @param classVisitor the <code>ClassVisitor</code> to which visits will be delegated.
     */
    public ConcreteClassDownTraveler(ClassVisitor classVisitor) {
        this.classVisitor = classVisitor;
    }

    // Implementations for ClassVisitor.

    public void visitProgramClass(ProgramClass programClass) {
        // Is this an abstract class or an interface?
        if ((programClass.getAccessFlags() & (ClassConstants.ACC_INTERFACE | ClassConstants.ACC_ABSTRACT)) != 0) {
            // Travel down the hierarchy.
            Clazz[] subClasses = programClass.subClasses;
            if (subClasses != null) {
                for (int index = 0; index < subClasses.length; index++) {
                    subClasses[index].accept(this);
                }
            }
        } else {
            // Visit the class. Don't descend any further.
            programClass.accept(classVisitor);
        }
    }

    public void visitLibraryClass(LibraryClass libraryClass) {
        // Is this an abstract class or interface?
        if ((libraryClass.getAccessFlags() & (ClassConstants.ACC_INTERFACE | ClassConstants.ACC_ABSTRACT)) != 0) {
            // Travel down the hierarchy.
            Clazz[] subClasses = libraryClass.subClasses;
            if (subClasses != null) {
                for (int index = 0; index < subClasses.length; index++) {
                    subClasses[index].accept(this);
                }
            }
        } else {
            // Visit the class. Don't descend any further.
            libraryClass.accept(classVisitor);
        }
    }
}
